With strong enough posts and some heavy duty T strap hinges you
shouldn't have any problem as long as the gate frame is braced well.
Use an X or Z bracing configuration and be sure to attach the slats or
sheeting at the perimeter AND to the braces to develop some shear
strength to keep it from racking. You could also consider adding a
wheel to each gate, although this is not always possible depending on
the grade situation.